check_block_presence.md

🔍 Use block_given? to Guard Behavior

block_given? checks if a block was passed without converting it to a Proc. This lightweight check avoids errors when calling yield and lets you choose between different execution paths. It’s ideal for methods that optionally accept blocks.

def maybe_log(msg)
  if block_given?
    puts "Before: #{msg}"
    yield
    puts "After: #{msg}"
  else
    puts msg
  end
end

maybe_log("Process") do
  puts "Running..."
end
# Before: Process
# Running...
# After: Process

maybe_log("Simple")
# Simple